Dietary Recommendation for Athletes

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Dietary Recommendation for Athletes

• Dr. David L. Gee
• FCSN/PE 446

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Training Diet Recommendations High Carbohydrate
Diet

• For Power Athletes
• Traditional recommendation
• 55 of calories
• Why?
• primary source of energy
• effect of repeated high intensity workouts on
  glycogen

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Training Diet Recommendations High Carbohydrate
Diet

• For Endurance Athletes
• Traditional recommendation
• 60 of calories
• Why?
• endurance training reduces glycogen
• repeated training effects

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ADA/ACSM Position PaperDietary Carbohydrates

• 6-10 gCHO/kg BW
• Upper end with high intensity
• Upper end with long duration
• Recommends against CHO guidelines
• 4000 Cal/day _at_ 50CHO for 70kg athlete
• 7.1 gCHO/kg
• 2000 Cal/day _at_ 60CHO for 60kg athlete
• 5 gCHO/kg

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Training Diet Recommendations High Carbohydrate
Diet

• Recovery Meal
• CHO ingested within 2hrs of workout is converted
  to glycogen 50 more rapidly.
• Rec up to 1.5 g CHO/kgBW of mixed CHO within 2
  hours (hi glycemic index?)
• Particularly important for multiple
  workouts/events per day
• Role for protein in recovery meal?

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Training Diet Recommendations High Carbohydrate
Diet Recovery Meal

• Example
• 50 kg x 1.5 gCHO/kg 75gCHO
• 5 servings of bread or fruit
• Whole/real foods preferred
• Cheapest, has other nutrients
• Sport Supplements
• Convenient
• Concentrated
• Expensive

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High CHO Energy Drinks
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Energy Bars 70 carbohydrate calories
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Sport Shakes
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Energy Gels
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Training Diet Recommendations Moderate Protein
Diet

• RDA 0.8 gP/kgBW
• For Power Athletes
• ACSM/ADA
• 1.6-1.7gP/kgBW
• maintenance of large muscle mass
• optimizes rate of protein synthesis (?)
• Is more protein a problem?

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Training Diet Recommendations Moderate Protein
Diet

• For Endurance Athletes
• ACSM/ADA
• 1.2-1.4gP/kgBW
• replaces proteins used as fuel during endurance
  training (10-15 of energy)

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Training Diet Recommendations Moderate Protein
Diet

• Most athletes do NOT need to consume
  supplementary amounts of protein
• typical US diet 15 of calories
• 4000 Cal diet 150g Pro in the diet
• 90 kg Power athlete needing 1.6gP/kg needs
  144g Pro

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Which athletes are at risk for inadequate protein
intake?

• Limited caloric intake
• low meat/dairy intake
• very low fat intake
• weight conscious athlete
• 2000 Calorie, 10 protein
• 200 PRO Cal 50g PRO provided
• 1.6 gPRO x 55 kg 88g PRO needed

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MetRx Protein Plus Powder

• INGREDIENTS METAMYOSYN (Unique Blend of Milk
  Protein Concentrate, Calcium Caseinate, Sodium
  Caseinate, Whey Protein Isolate, L-Glutamine,
  Dried Egg Whites), Natural and Artificial
  Flavors, Partially Hydrogenated Oil (soybean and
  cottonseed oils), Aspartame, Sodium
  Carboxymethylcellulose, Guar Gum, Xanthan Gum.
• 40/container, 16 servings/container,
  46gP/serving 2.50/serving, 75/month,
  900/year
• 8 oz sirloin steak, 5/lb, 56gP, 2.50
• 5 c NF milk, 2/gal, 40gP, 0.63

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Training Diet RecommendationsLow Fat Diet

• 55-60 CHO, 10-15 PRO
• Advantages of moderately low fat (compared to
  very low fat)
• High caloric density
• Wider variety of foods available
• May be more palatable

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Training Diet RecommendationsSummary

• Carbohydrates
• Moderate to high in carbohydrates
• 6-10g CHO/kg BW
• Protein
• Higher than RDA, moderately high
• Power athletes 1.6-1.7gP/kgBW
• Endurance athletes 1.2-1.4gP/kgBW
• Fat
• Balance of calories, relatively low fat

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Case Study Brian Competitive Stair Runner

• Works 7AM to 330PM
• Construction contractor in Boston suburbs
• Training Schedule
• 5X/week for 2 hours on stairs
• 3 hour RT commute to city
• Trains weekends by cycling/trail runs
• Diet
• Realizes he needs hi CHO diet
• Eats convenience foods

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Brians Diet and Training Schedule

• 630AM lg bowl cereal, banana, whole milk
• 7AM coffee w/creamsugar, doughnut
• 12noon spaghetti with butter, 1-2 slices bread
  w/butter, 4 Oreo cookies, 2c whole milk
• 4-530PM drives to Boston
• 530-730PM trains
• 730-9PM 16 oz sport drink while driving home
• 10PM mac cheese (frozen dinner), handful of
  crackers, 2 c milk, 4 Oreos, or a fast-food
  burger, fries, 2c milk

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Brians Diet Analysis

• 4000 Cal, 50 CHO, 15 PRO, 35 Fat
• Assume 160 lbs 73kg
• PRO needs 1.4gPRO/kg x 73 102gPRO
• PRO intake 4000 x 15 600 Cal PRO
• 150 g PRO, protein intake is OK
• Or 150g/73kg 2.1 gP/kgBW
• CHO intake 4000 x 50 2000 Cal CHO
• 500 g CHO
• 6.8 g CHO/kg
• CHO intake OK, but perhaps marginal
• Goal
• Increase CHO, decrease FAT intake
• Recognize need for convenience

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Case Study Weight Gain for a Professional
Basketball Player

• 25 yo CBA rookie
• 71 (2.2m)
• 215 lbs (98kg)
• BMI 20
• Goal weight 235 lbs

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24 hour diet recall
PRO 97g/98kg1.0gP/kg CHO 1011g/9810.3g/kg
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Diet analysis of 24-hr recall
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Revised food list
PRO 174g/98kg 1.8gP/kg CHO 782g/98kg
8.0gP/kg
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Revised diet analysis
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Pre-Event Meal

• Goals
• Top off glycogen stores
• Optimize hydration
• Empty upper GI tract

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Pre-Event Meal

• Meal Composition
• High in carbohydrates
• mixed complex and simple
• Reasonably low in fats and protein
• Low in dietary fiber

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Pre-Event Meal

• Composition (cont.)
• High in fluids
• Individualize
• Use familiar foods

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Pre-Event Meal

• Timing of meal
• Complete 2 hours before event
• Individualize

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Carbohydrates Just Prior to Event

• Purpose provide exogeneous CHO to avoid
  hypoglycemia and delay glycogen depletion.
• For endurance athletes only
• Absorption delayed
• Response highly individualized
• Caution
• May promote reactive hypoglycemia in sensitive
  individuals

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Meals/CHO before/during/after events

• Pre-event/Pre-game meal
• 2-3 hours before event
• CHO immediately prior to event
• 5-15 minutes before event
• CHO during event
• Post-workout meal
• Within 2 hours of workout

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Carbohydrates During Event

• Sport drinks, energy bars, fruits, breads
• Metabolically useful for
• endurance athletes
• May spare muscle/liver glycogen
• May provide extra CHO for more power
• those prone to hypoglycemia
• Exogenous source of glucose for blood
• Dilute concentration (because it also promotes fluid absorption

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Types of Carbohydrate

• Fructose
• Absorbed more slowly than glucose
• Reduced insulin response
• Reduced chance of reactive hypoglycemia
• May produce more stable blood sugar if consumed
  45 minutes prior to exercise
• May cause osmotic diarrhea in susceptible
  individuals in high dosages
• Free fructose, high fructose corn syrup (50),
  sucrose

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Types of Carbohydrate

• Glucose Polymers
• Short polymers of glucose
• Partial hydrolysis of starch
• Soluble, low osmolarity, rapid gastric emptying,
  digestion, and absorption
• Most, but not all studies, suggest that glucose
  polymers may be superior to glucose, fructose,
  and sucrose

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Types of Carbohydrate

• Solid vs Liquid Carbohydrates
• Most studies suggests little difference between
  solid vs liquid carbohydrates
• Those that show difference tend to suggest that
  liquids are more rapidly absorbed
• Ultra-endurance athletes may develop aversion to
  liquid sweet carbohydrates

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Types of Carbohydrate

• Low Glycemic Index Food
• Slowly absorbed resulting in lower, but prolonged
  elevation of blood glucose
• Research findings vary when comparing hi-, mod-,
  and low- GI foods and performance

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Types of Carbohydrate

• Individualize type of carbohydrate used
• Individual differences
• Sport differences
• Use before/during workouts
• Note outcomes

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Carbohydrate Loading

• Theory
• Glycogen depletion is a cause of fatigue in
  endurance athletes.
• Increasing glycogen stores above normal levels
  will enhance performance in endurance athletes.

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Diet, muscle glycogen, and endurance
performance.Karlson Saltin. J. Appl. Physiol.
1971-31203-206.

• Subjects Trained distance runners
• Protocol normal vs high carb diet
• Performance test 30km run
• Outcomes
• Muscle glycogen after hi-carb diet was double
  that than after normal diet
• All runners finished 30km faster after hi-carb
  diet by an average of 8 minutes
• No benefit seen in first hour of run, but able to
  maintain pace toward end of run.

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Carbohydrate Loading Protocol Classic Method

• Depletion Phase (3-4 days)
• Strenuous endurance training
• Very low carbohydrate diet
• Repletion Phase (3-4 days)
• Tapered training -- rest
• Very high carbohydrate diet
• 8-10g CHO/kg

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Carbohydrate Loading Protocol Classic Method
Drawbacks

• High level of fatigue during depletion phase
• May result in hypoglycemia and ketoacidosis
  during depletion phase (nausea, fatigue,
  dizziness, irritability)
• Very unusual diet during depletion phase
• Unappetizing
• May cause GI distress

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Carbohydrate Loading Protocol Classic Method
Drawbacks

• May not result in substantially higher glycogen
  levels than Modified Method
• Effect of different dietary CHO plans and muscle
  glycogen content (Sharman, 1981)
• Protocol trained runners, 73 VO2max for 90, 40,
  40, 20, 20, 0 minutes
• Muscle glycogen content
• 50 CHO diet for 6 days 160 mmol/kg
• 50 CHO for 3 days, 70 CHO for 3 days 203
  mmol/kg
• 15 CHO for 3 days, 70 CHO for 3 days 207
  mmol/kg

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Carbohydrate Loading Protocol Modified Method

• Mild Depletion Phase
• Normal training with tapering
• Moderate carbohydrate diet (4gCHO/kg BW)
• Repletion Phase
• Light training -- rest
• Very high CHO diet
• 8-10gCHO/kg BW
• 400-700gCHO/day
• 70-80 of total Calories

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Carbohydrate Loading

• Diet a mixture of complex and simple
  carbohydrates to maximize liver and muscle
  glycogen
• Effect of Dietary CHO-type on Rate of Glycogen
  Synthesis (Costill, 1981)
• Protocol trained endurance athletes, 10 mile run
  _at_ 80 VO2max five 1-minute sprints with 3
  minute rests
• Muscle glycogen content
• 24 hours
• High simple CHO diet 133 mmol/kg
• High complex CHO diet 138 mmol/kg
• 48 hours
• High simple CHO diet 145 mmol/kg
• High complex CHO diet 165 mmol/kg

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Carbohydrate Loading

• Concerns
• 2-3 lbs of weight gain (water)
• 3 grams of water for every extra gram of glycogen
  stored
• 300-400 grams of glycogen 900-1200 grams of
  water
• 1.2-1.6kg weight gain (2.5-3.5 pounds)
• stiffness
• hyper-hydration
• nausea and diarrhea with diet changes
• Useful ONLY FOR ENDURANCE ATHLETES! (events over
  60 minutes)